Re: [x86_64 PATCH] More TImode parameter passing improvements.
On Thu, Jul 20, 2023 at 9:44 AM Roger Sayle wrote: > > > Hi Uros, > > > From: Uros Bizjak > > Sent: 20 July 2023 07:50 > > > > On Wed, Jul 19, 2023 at 10:07 PM Roger Sayle > > wrote: > > > > > > This patch is the next piece of a solution to the x86_64 ABI issues in > > > PR 88873. This splits the *concat3_3 define_insn_and_split > > > into two patterns, a TARGET_64BIT *concatditi3_3 and a !TARGET_64BIT > > > *concatsidi3_3. This allows us to add an additional alternative to > > > the the 64-bit version, enabling the register allocator to perform > > > this operation using SSE registers, which is implemented/split after > > > reload using vec_concatv2di. > > > > > > To demonstrate the improvement, the test case from PR88873: > > > > > > typedef struct { double x, y; } s_t; > > > > > > s_t foo (s_t a, s_t b, s_t c) > > > { > > > return (s_t){ __builtin_fma(a.x, b.x, c.x), __builtin_fma (a.y, b.y, > > > c.y) }; } > > > > > > when compiled with -O2 -march=cascadelake, currently generates: > > > > > > foo:vmovq %xmm2, -56(%rsp) > > > movq-56(%rsp), %rax > > > vmovq %xmm3, -48(%rsp) > > > vmovq %xmm4, -40(%rsp) > > > movq-48(%rsp), %rcx > > > vmovq %xmm5, -32(%rsp) > > > vmovq %rax, %xmm6 > > > movq-40(%rsp), %rax > > > movq-32(%rsp), %rsi > > > vpinsrq $1, %rcx, %xmm6, %xmm6 > > > vmovq %xmm0, -24(%rsp) > > > vmovq %rax, %xmm7 > > > vmovq %xmm1, -16(%rsp) > > > vmovapd %xmm6, %xmm2 > > > vpinsrq $1, %rsi, %xmm7, %xmm7 > > > vfmadd132pd -24(%rsp), %xmm7, %xmm2 > > > vmovapd %xmm2, -56(%rsp) > > > vmovsd -48(%rsp), %xmm1 > > > vmovsd -56(%rsp), %xmm0 > > > ret > > > > > > with this change, we avoid many of the reloads via memory, > > > > > > foo:vpunpcklqdq %xmm3, %xmm2, %xmm7 > > > vpunpcklqdq %xmm1, %xmm0, %xmm6 > > > vpunpcklqdq %xmm5, %xmm4, %xmm2 > > > vmovdqa %xmm7, -24(%rsp) > > > vmovdqa %xmm6, %xmm1 > > > movq-16(%rsp), %rax > > > vpinsrq $1, %rax, %xmm7, %xmm4 > > > vmovapd %xmm4, %xmm6 > > > vfmadd132pd %xmm1, %xmm2, %xmm6 > > > vmovapd %xmm6, -24(%rsp) > > > vmovsd -16(%rsp), %xmm1 > > > vmovsd -24(%rsp), %xmm0 > > > ret > > > > > > > > > This patch has been tested on x86_64-pc-linux-gnu with make bootstrap > > > and make -k check, both with and without --target_board=unix{-m32} > > > with no new failures. Ok for mainline? > > > > > > > > > 2023-07-19 Roger Sayle > > > > > > gcc/ChangeLog > > > * config/i386/i386-expand.cc (ix86_expand_move): Don't call > > > force_reg, to use SUBREG rather than create a new pseudo when > > > inserting DFmode fields into TImode with insvti_{high,low}part. > > > (*concat3_3): Split into two define_insn_and_split... > > > (*concatditi3_3): 64-bit implementation. Provide alternative > > > that allows register allocation to use SSE registers that is > > > split into vec_concatv2di after reload. > > > (*concatsidi3_3): 32-bit implementation. > > > > > > gcc/testsuite/ChangeLog > > > * gcc.target/i386/pr88873.c: New test case. > > > > diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc > > index f9b0dc6..9c3febe 100644 > > --- a/gcc/config/i386/i386-expand.cc > > +++ b/gcc/config/i386/i386-expand.cc > > @@ -558,7 +558,7 @@ ix86_expand_move (machine_mode mode, rtx > > operands[]) > >op0 = SUBREG_REG (op0); > >tmp = gen_rtx_AND (TImode, copy_rtx (op0), tmp); > >if (mode == DFmode) > > -op1 = force_reg (DImode, gen_lowpart (DImode, op1)); > > +op1 = gen_lowpart (DImode, op1); > > > > Please note that gen_lowpart will ICE when op1 is a SUBREG. This is the > > reason > > that we need to first force a SUBREG to a register and then perform > > gen_lowpart, > > and it is necessary to avoid ICE. > > The good news is that we know op1 is a register, as this is tested by > "&& REG_P (op1)" on line 551. You'll also notice that I'm not removing > the force_reg from before the call to gen_lowpart, but removing the call > to force_reg after the call to gen_lowpart. When I originally wrote this, > the hope was that placing this SUBREG in its own pseudo would help > with register allocation/CSE. Unfortunately, increasing the number of > pseudos (in this case) increases compile-time (due to quadratic behaviour > in LRA), as shown by PR rtl-optimization/110587, and keeping the DF->DI > conversion in a SUBREG inside the insvti_{high,low}part allows the > register allocator to see the DF->DI->TI sequence in a single pattern, > and hence choose to keep the TI mode in SSE registers, rather than use > a pair of reloads, to write the DF value to memory, then read it back as > a scalar in DImode, and perhaps the same again to go the other way. This was my on
RE: [x86_64 PATCH] More TImode parameter passing improvements.
Hi Uros, > From: Uros Bizjak > Sent: 20 July 2023 07:50 > > On Wed, Jul 19, 2023 at 10:07 PM Roger Sayle > wrote: > > > > This patch is the next piece of a solution to the x86_64 ABI issues in > > PR 88873. This splits the *concat3_3 define_insn_and_split > > into two patterns, a TARGET_64BIT *concatditi3_3 and a !TARGET_64BIT > > *concatsidi3_3. This allows us to add an additional alternative to > > the the 64-bit version, enabling the register allocator to perform > > this operation using SSE registers, which is implemented/split after > > reload using vec_concatv2di. > > > > To demonstrate the improvement, the test case from PR88873: > > > > typedef struct { double x, y; } s_t; > > > > s_t foo (s_t a, s_t b, s_t c) > > { > > return (s_t){ __builtin_fma(a.x, b.x, c.x), __builtin_fma (a.y, b.y, > > c.y) }; } > > > > when compiled with -O2 -march=cascadelake, currently generates: > > > > foo:vmovq %xmm2, -56(%rsp) > > movq-56(%rsp), %rax > > vmovq %xmm3, -48(%rsp) > > vmovq %xmm4, -40(%rsp) > > movq-48(%rsp), %rcx > > vmovq %xmm5, -32(%rsp) > > vmovq %rax, %xmm6 > > movq-40(%rsp), %rax > > movq-32(%rsp), %rsi > > vpinsrq $1, %rcx, %xmm6, %xmm6 > > vmovq %xmm0, -24(%rsp) > > vmovq %rax, %xmm7 > > vmovq %xmm1, -16(%rsp) > > vmovapd %xmm6, %xmm2 > > vpinsrq $1, %rsi, %xmm7, %xmm7 > > vfmadd132pd -24(%rsp), %xmm7, %xmm2 > > vmovapd %xmm2, -56(%rsp) > > vmovsd -48(%rsp), %xmm1 > > vmovsd -56(%rsp), %xmm0 > > ret > > > > with this change, we avoid many of the reloads via memory, > > > > foo:vpunpcklqdq %xmm3, %xmm2, %xmm7 > > vpunpcklqdq %xmm1, %xmm0, %xmm6 > > vpunpcklqdq %xmm5, %xmm4, %xmm2 > > vmovdqa %xmm7, -24(%rsp) > > vmovdqa %xmm6, %xmm1 > > movq-16(%rsp), %rax > > vpinsrq $1, %rax, %xmm7, %xmm4 > > vmovapd %xmm4, %xmm6 > > vfmadd132pd %xmm1, %xmm2, %xmm6 > > vmovapd %xmm6, -24(%rsp) > > vmovsd -16(%rsp), %xmm1 > > vmovsd -24(%rsp), %xmm0 > > ret > > > > > > This patch has been tested on x86_64-pc-linux-gnu with make bootstrap > > and make -k check, both with and without --target_board=unix{-m32} > > with no new failures. Ok for mainline? > > > > > > 2023-07-19 Roger Sayle > > > > gcc/ChangeLog > > * config/i386/i386-expand.cc (ix86_expand_move): Don't call > > force_reg, to use SUBREG rather than create a new pseudo when > > inserting DFmode fields into TImode with insvti_{high,low}part. > > (*concat3_3): Split into two define_insn_and_split... > > (*concatditi3_3): 64-bit implementation. Provide alternative > > that allows register allocation to use SSE registers that is > > split into vec_concatv2di after reload. > > (*concatsidi3_3): 32-bit implementation. > > > > gcc/testsuite/ChangeLog > > * gcc.target/i386/pr88873.c: New test case. > > diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc > index f9b0dc6..9c3febe 100644 > --- a/gcc/config/i386/i386-expand.cc > +++ b/gcc/config/i386/i386-expand.cc > @@ -558,7 +558,7 @@ ix86_expand_move (machine_mode mode, rtx > operands[]) >op0 = SUBREG_REG (op0); >tmp = gen_rtx_AND (TImode, copy_rtx (op0), tmp); >if (mode == DFmode) > -op1 = force_reg (DImode, gen_lowpart (DImode, op1)); > +op1 = gen_lowpart (DImode, op1); > > Please note that gen_lowpart will ICE when op1 is a SUBREG. This is the reason > that we need to first force a SUBREG to a register and then perform > gen_lowpart, > and it is necessary to avoid ICE. The good news is that we know op1 is a register, as this is tested by "&& REG_P (op1)" on line 551. You'll also notice that I'm not removing the force_reg from before the call to gen_lowpart, but removing the call to force_reg after the call to gen_lowpart. When I originally wrote this, the hope was that placing this SUBREG in its own pseudo would help with register allocation/CSE. Unfortunately, increasing the number of pseudos (in this case) increases compile-time (due to quadratic behaviour in LRA), as shown by PR rtl-optimization/110587, and keeping the DF->DI conversion in a SUBREG inside the insvti_{high,low}part allows the register allocator to see the DF->DI->TI sequence in a single pattern, and hence choose to keep the TI mode in SSE registers, rather than use a pair of reloads, to write the DF value to memory, then read it back as a scalar in DImode, and perhaps the same again to go the other way. >op1 = gen_rtx_ZERO_EXTEND (TImode, op1); >op1 = gen_rtx_IOR (TImode, tmp, op1); > } > @@ -570,7 +570,7 @@ ix86_expand_move (machine_mode mode, rtx > operands[]) >op0 = SUBREG_REG (op0); >tmp = gen_rtx_AND (TImode, copy_rtx (op0), tmp); >if (mode == DFmode) > -op1 = force
Re: [x86_64 PATCH] More TImode parameter passing improvements.
On Wed, Jul 19, 2023 at 10:07 PM Roger Sayle wrote: > > > This patch is the next piece of a solution to the x86_64 ABI issues in > PR 88873. This splits the *concat3_3 define_insn_and_split > into two patterns, a TARGET_64BIT *concatditi3_3 and a !TARGET_64BIT > *concatsidi3_3. This allows us to add an additional alternative to the > the 64-bit version, enabling the register allocator to perform this > operation using SSE registers, which is implemented/split after reload > using vec_concatv2di. > > To demonstrate the improvement, the test case from PR88873: > > typedef struct { double x, y; } s_t; > > s_t foo (s_t a, s_t b, s_t c) > { > return (s_t){ __builtin_fma(a.x, b.x, c.x), __builtin_fma (a.y, b.y, c.y) > }; > } > > when compiled with -O2 -march=cascadelake, currently generates: > > foo:vmovq %xmm2, -56(%rsp) > movq-56(%rsp), %rax > vmovq %xmm3, -48(%rsp) > vmovq %xmm4, -40(%rsp) > movq-48(%rsp), %rcx > vmovq %xmm5, -32(%rsp) > vmovq %rax, %xmm6 > movq-40(%rsp), %rax > movq-32(%rsp), %rsi > vpinsrq $1, %rcx, %xmm6, %xmm6 > vmovq %xmm0, -24(%rsp) > vmovq %rax, %xmm7 > vmovq %xmm1, -16(%rsp) > vmovapd %xmm6, %xmm2 > vpinsrq $1, %rsi, %xmm7, %xmm7 > vfmadd132pd -24(%rsp), %xmm7, %xmm2 > vmovapd %xmm2, -56(%rsp) > vmovsd -48(%rsp), %xmm1 > vmovsd -56(%rsp), %xmm0 > ret > > with this change, we avoid many of the reloads via memory, > > foo:vpunpcklqdq %xmm3, %xmm2, %xmm7 > vpunpcklqdq %xmm1, %xmm0, %xmm6 > vpunpcklqdq %xmm5, %xmm4, %xmm2 > vmovdqa %xmm7, -24(%rsp) > vmovdqa %xmm6, %xmm1 > movq-16(%rsp), %rax > vpinsrq $1, %rax, %xmm7, %xmm4 > vmovapd %xmm4, %xmm6 > vfmadd132pd %xmm1, %xmm2, %xmm6 > vmovapd %xmm6, -24(%rsp) > vmovsd -16(%rsp), %xmm1 > vmovsd -24(%rsp), %xmm0 > ret > > > This patch has been tested on x86_64-pc-linux-gnu with make bootstrap > and make -k check, both with and without --target_board=unix{-m32} > with no new failures. Ok for mainline? > > > 2023-07-19 Roger Sayle > > gcc/ChangeLog > * config/i386/i386-expand.cc (ix86_expand_move): Don't call > force_reg, to use SUBREG rather than create a new pseudo when > inserting DFmode fields into TImode with insvti_{high,low}part. > (*concat3_3): Split into two define_insn_and_split... > (*concatditi3_3): 64-bit implementation. Provide alternative > that allows register allocation to use SSE registers that is > split into vec_concatv2di after reload. > (*concatsidi3_3): 32-bit implementation. > > gcc/testsuite/ChangeLog > * gcc.target/i386/pr88873.c: New test case. diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc index f9b0dc6..9c3febe 100644 --- a/gcc/config/i386/i386-expand.cc +++ b/gcc/config/i386/i386-expand.cc @@ -558,7 +558,7 @@ ix86_expand_move (machine_mode mode, rtx operands[]) op0 = SUBREG_REG (op0); tmp = gen_rtx_AND (TImode, copy_rtx (op0), tmp); if (mode == DFmode) -op1 = force_reg (DImode, gen_lowpart (DImode, op1)); +op1 = gen_lowpart (DImode, op1); Please note that gen_lowpart will ICE when op1 is a SUBREG. This is the reason that we need to first force a SUBREG to a register and then perform gen_lowpart, and it is necessary to avoid ICE. op1 = gen_rtx_ZERO_EXTEND (TImode, op1); op1 = gen_rtx_IOR (TImode, tmp, op1); } @@ -570,7 +570,7 @@ ix86_expand_move (machine_mode mode, rtx operands[]) op0 = SUBREG_REG (op0); tmp = gen_rtx_AND (TImode, copy_rtx (op0), tmp); if (mode == DFmode) -op1 = force_reg (DImode, gen_lowpart (DImode, op1)); +op1 = gen_lowpart (DImode, op1); Also here. op1 = gen_rtx_ZERO_EXTEND (TImode, op1); op1 = gen_rtx_ASHIFT (TImode, op1, GEN_INT (64)); op1 = gen_rtx_IOR (TImode, tmp, op1); Uros.
[x86_64 PATCH] More TImode parameter passing improvements.
This patch is the next piece of a solution to the x86_64 ABI issues in PR 88873. This splits the *concat3_3 define_insn_and_split into two patterns, a TARGET_64BIT *concatditi3_3 and a !TARGET_64BIT *concatsidi3_3. This allows us to add an additional alternative to the the 64-bit version, enabling the register allocator to perform this operation using SSE registers, which is implemented/split after reload using vec_concatv2di. To demonstrate the improvement, the test case from PR88873: typedef struct { double x, y; } s_t; s_t foo (s_t a, s_t b, s_t c) { return (s_t){ __builtin_fma(a.x, b.x, c.x), __builtin_fma (a.y, b.y, c.y) }; } when compiled with -O2 -march=cascadelake, currently generates: foo:vmovq %xmm2, -56(%rsp) movq-56(%rsp), %rax vmovq %xmm3, -48(%rsp) vmovq %xmm4, -40(%rsp) movq-48(%rsp), %rcx vmovq %xmm5, -32(%rsp) vmovq %rax, %xmm6 movq-40(%rsp), %rax movq-32(%rsp), %rsi vpinsrq $1, %rcx, %xmm6, %xmm6 vmovq %xmm0, -24(%rsp) vmovq %rax, %xmm7 vmovq %xmm1, -16(%rsp) vmovapd %xmm6, %xmm2 vpinsrq $1, %rsi, %xmm7, %xmm7 vfmadd132pd -24(%rsp), %xmm7, %xmm2 vmovapd %xmm2, -56(%rsp) vmovsd -48(%rsp), %xmm1 vmovsd -56(%rsp), %xmm0 ret with this change, we avoid many of the reloads via memory, foo:vpunpcklqdq %xmm3, %xmm2, %xmm7 vpunpcklqdq %xmm1, %xmm0, %xmm6 vpunpcklqdq %xmm5, %xmm4, %xmm2 vmovdqa %xmm7, -24(%rsp) vmovdqa %xmm6, %xmm1 movq-16(%rsp), %rax vpinsrq $1, %rax, %xmm7, %xmm4 vmovapd %xmm4, %xmm6 vfmadd132pd %xmm1, %xmm2, %xmm6 vmovapd %xmm6, -24(%rsp) vmovsd -16(%rsp), %xmm1 vmovsd -24(%rsp), %xmm0 ret This patch has been tested on x86_64-pc-linux-gnu with make bootstrap and make -k check, both with and without --target_board=unix{-m32} with no new failures. Ok for mainline? 2023-07-19 Roger Sayle gcc/ChangeLog * config/i386/i386-expand.cc (ix86_expand_move): Don't call force_reg, to use SUBREG rather than create a new pseudo when inserting DFmode fields into TImode with insvti_{high,low}part. (*concat3_3): Split into two define_insn_and_split... (*concatditi3_3): 64-bit implementation. Provide alternative that allows register allocation to use SSE registers that is split into vec_concatv2di after reload. (*concatsidi3_3): 32-bit implementation. gcc/testsuite/ChangeLog * gcc.target/i386/pr88873.c: New test case. Thanks in advance, Roger -- diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc index f9b0dc6..9c3febe 100644 --- a/gcc/config/i386/i386-expand.cc +++ b/gcc/config/i386/i386-expand.cc @@ -558,7 +558,7 @@ ix86_expand_move (machine_mode mode, rtx operands[]) op0 = SUBREG_REG (op0); tmp = gen_rtx_AND (TImode, copy_rtx (op0), tmp); if (mode == DFmode) - op1 = force_reg (DImode, gen_lowpart (DImode, op1)); + op1 = gen_lowpart (DImode, op1); op1 = gen_rtx_ZERO_EXTEND (TImode, op1); op1 = gen_rtx_IOR (TImode, tmp, op1); } @@ -570,7 +570,7 @@ ix86_expand_move (machine_mode mode, rtx operands[]) op0 = SUBREG_REG (op0); tmp = gen_rtx_AND (TImode, copy_rtx (op0), tmp); if (mode == DFmode) - op1 = force_reg (DImode, gen_lowpart (DImode, op1)); + op1 = gen_lowpart (DImode, op1); op1 = gen_rtx_ZERO_EXTEND (TImode, op1); op1 = gen_rtx_ASHIFT (TImode, op1, GEN_INT (64)); op1 = gen_rtx_IOR (TImode, tmp, op1); diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md index 47ea050..8c54aa5 100644 --- a/gcc/config/i386/i386.md +++ b/gcc/config/i386/i386.md @@ -12408,21 +12408,47 @@ DONE; }) -(define_insn_and_split "*concat3_3" - [(set (match_operand: 0 "nonimmediate_operand" "=ro,r,r,&r") - (any_or_plus: - (ashift: - (zero_extend: - (match_operand:DWIH 1 "nonimmediate_operand" "r,m,r,m")) +(define_insn_and_split "*concatditi3_3" + [(set (match_operand:TI 0 "nonimmediate_operand" "=ro,r,r,&r,x") + (any_or_plus:TI + (ashift:TI + (zero_extend:TI + (match_operand:DI 1 "nonimmediate_operand" "r,m,r,m,x")) (match_operand:QI 2 "const_int_operand")) - (zero_extend: - (match_operand:DWIH 3 "nonimmediate_operand" "r,r,m,m"] - "INTVAL (operands[2]) == * BITS_PER_UNIT" + (zero_extend:TI + (match_operand:DI 3 "nonimmediate_operand" "r,r,m,m,0"] + "TARGET_64BIT + && INTVAL (operands[2]) == 64" + "#" + "&& reload_completed" + [(const_int 0)] +{ + if (SSE_REG_P (operands[0])) +{ + rtx tmp = gen_rtx_REG (V2DImode, REGNO (operands[0])); + emit_insn (gen_vec_concatv2di (tmp,